Preliminary
FEATURES
D
Provides Reference Clock And Synthesized Clock
D
5 to 32 MHz Input Reference Frequency
D
Pin-to-Pin Compatible to Avasem AV9107
D
Programmable Analog Phase Locked Loop
ST49C107A-04
June 1997-3
Preprogrammed CPU Mother Board
Frequency Generator
...the analog plus company
TM
D
Low Power Single 5V CMOS Technology
D
Up to 16 Frequencies Stored Internally
D
8/14 pin DIP or SOIC Package
GENERAL DESCRIPTION
The ST49C107A-04 is a mask programmable monolithic
analog CMOS device designed to generate two
simultaneous clocks. The output frequency can vary from
2 to 130MHz, with up to 16 single selectable
preprogrammed frequencies stored in internal ROM.
The ST49C107A-04 is designed to replace existing CPU
mother board clocks generated from individual oscillators
ORDERING INFORMATION
Part No.
ST49C107ACF14-04
Package
14 Lead 150 Mil JEDEC SOIC
Operating
Temperature Range
0°C to 70°C
in order to reduce board space and number of oscillators.
To provide high speed and low jitter clock, the parts utilize
a high speed analog CMOS phase locked loop using
14.318 MHz system clock as the reference clock (note
that reference clock can be changed to generate optional
frequencies from a standard programmed device). The
programmed clock outputs are selectable via four
address lines.
BLOCK DIAGRAM
XTAL
XTAL
OE1 OE2
Oscillator
Circuit
Output
Buffer
1X-CLOCK
2X-CLOCK
Programmable
Counter
B
Phase
Detector
Charge
Pump
Loop
Filter
Voltage
Controlled
Oscillator
Programmable
Counter
C
Programmable
Counter
A
Voltage
Reference
Circuit
Rom Table
Select
Logic
B=5....128
A=5....128
C = 1, 2, 4
A0-A3
Figure 1. Block Diagram
Rev. P2.00
E1996
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538
z
(510) 668-7000
z
FAX (510) 668-7017
1
ST49C107A-04
PIN CONFIGURATION
Preliminary
A1
A2
A3
AGND
DGND
PD*
XTAL1
1
2
3
4
5
6
7
14
13
12
11
10
9
8
A0
1XCLK
V
CC
2XCLK
OE2
OE1
XTAL2
14 Lead SOIC (Jedec, 0.150”)
PIN DESCRIPTION
Symbol
A1
A2
A3
AGND
DGND
PD
XTAL1
Pin #
1
2
3
4
5
6
7
Type
I
I
I
O
O
I
I
Frequency Select Address Input 2
1
.
Frequency Select Address Input 3
1
.
Frequency Select Address Input 4
1
.
Analog Ground.
Digital Ground.
Power-down (Active Low).
Shuts off chip when low
1
.
Crystal Or External Clock Input.
A crystal can be connected to this pin and XTAL2 pin to
generate internal phase locked loop reference clock. For external 14.318 MHz clock, XTAL2
is left open or used as buffered clock output.
Crystal Output.
1X-CLOCK Output Enable (Active High).
1X-CLOCK output is three stated when this pin is
low
1
.
2X-CLOCK Output Enable (Active High).
2X-CLOCK output is three stated when this pin is
low
1
.
Programmed Output Clock.
Positive Supply Voltage.
Single +5 volts.
2X-CLOCK Divide-by-two Output.
Frequency Select Address Input 1
1
.
Description
XTAL2
OE1
OE2
2XCLK
V
CC
1XCLK
A0
8
9
10
11
12
13
14
O
I
I
O
I
O
I
Notes
1
Have internal pull-up resistors on inputs.
Rev. P2.00
2
Preliminary
DC ELECTRICAL CHARACTERISTICS
ST49C107A-04
Test Conditions: T
A
= 0°C to +70°C, V
CC
= 5.0V
10% Unless Otherwise Specified
Symbol
V
IL
V
IH
V
OL
V
OH
I
IL
I
IH
I
CC
I
SB
R
IN
Parameter
Input Low Level
Input High Level
Output Low Level
Output High Level
Input Low Current
Input High Current
Operating Current
Standby Current
Input Pull-up Resistance
500
45
25
900
1300
2.4
-10
1
55
2.0
0.4
Min.
Typ.
Max.
0.8
Unit
V
V
V
V
µA
µA
mA
µA
kΩ
I
OL
= 8.0mA
I
OH
= 8.0mA
Except Crystal Input
V
IN
=V
CC
No Load. CLOCK=100MHz
No Load
Conditions
DC ELECTRICAL CHARACTERISTICS
Test Conditions: T
A
= 0°C to +70°C, V
CC
= 5.0V
10% Unless Otherwise Specified
Symbol
T
1
T
2
T
4
T
5
T
3
T
3
T
T
7
T
8
Parameter
1X, 2X-CLOCK Rise Time
1X, 2X-CLOCK Fall Time
Duty Cycle
Duty Cycle
Jitter 1 Sigma
Jitter Absolute
Input Frequency
Buffered Clock Rise Time
Buffered Clock Fall Time
2
40
45
Min.
Typ.
1
1
50
50
0.5
3
Max.
2
2
60
55
2
5
32
20
20
Unit
ns
ns
%
%
%
%
MHz
ns
ns
Conditions
CL=20pF 0.8V - 2.0V
CL=20pF 2.0V - 0.8V
1.4V Switch Point
V
CC
/2 Switch Point
Specifications are subject to change without notice
ABSOLUTE MAXIMUM RATINGS
Supply Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Volts
Voltage at Any Pin . . . . . . . . . GND-0.3V to V
CC
+0.3V
Operating Temperature . . . . . . . . . . . . . 0°C to +70°C
Storage Temperature . . . . . . . . . . . . -40°C to +150°C
Package Dissipation . . . . . . . . . . . . . . . . . . . . . 500 mW
Rev. P2.00
3
ST49C107A-04
EXTERNAL CLOCK CONNECTION
Preliminary
CLOCK OUTPUT TABLE FOR ST49C107A-04 (using
14.318 MHz input. All frequencies in MHz).
A3
0
0
0
A2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
A1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
A0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Factor
95/17
107/23
35/10
95/34
56/8
107/46
38/17
35/20
76/17
2
3
8
1/2
1/4
109/13
118/13
2X-
CLOCK
80.02
66.62
50.11
40.01
100.23
33.31
32.01
25.06
64.02
2X-Input
3X-Input
8X-Input
0.5X-Input
0.25X-
Input
120.00
129.96
CLOCK
40.01
33.31
25.06
20.00
50.11
16.66
16.00
12.47
32.01
1X-Input
1.5X-Input
4X-Input
0.25X-Input
0.125X-
Input
60.00
64.98
To minimize the noise pickup, it is recommended to
connect 0.047 (F capacitor to XTAL1, and keep the lead
length of the capacitor to XTAL1 to a minimum to reduce
noise susceptibility.
FREQUENCY SELECT CALCULATION
The ST49C107A-04 contains an analog phase locked
loop circuit with digital closed loop dividers and a final
output multiplexer to achieve the desired dividing ratios
for the clock output.
The accuracy of the frequencies produced by the
ST49C107A-04 depends on the input frequency and
divider ratios. The formula for calculating the exact output
frequency is as follows:
CLKOUT = CLKIN * Factor
For proper output frequency, the ST49C107A-04 can
accept a reference frequency from 5 - 32MHz with max
output frequency of 130MHz (2X – clock).
0
0
0
0
0
1
1
1
1
1
1
1
1
1X–CLOCK
2X–CLOCK
CLOCK
T5
T1
T4
T2
T3
BCLK
T8
T7
Figure 2. Timing Diagram
Rev. P2.00
4
Preliminary
ST49C107A-04
14 LEAD SMALL OUTLINE
(150 MIL JEDEC SOIC)
Rev. 1.00
D
14
8
E
1
7
H
C
Seating
Plane
e
B
A
1
L
A
α
INCHES
SYMBOL
A
A
1
B
C
D
E
e
H
L
α
MIN
0.053
0.004
0.013
0.007
0.337
0.150
MAX
0.069
0.010
0.020
0.010
0.344
0.157
MILLIMETERS
MIN
1.35
0.10
0.33
0.19
8.55
3.80
MAX
1.75
0.25
0.51
0.25
8.75
4.00
0.050 BSC
0.228
0.016
0
°
0.244
0.050
8
°
1.27 BSC
5.80
0.40
0
°
6.20
1.27
8
°
Note: The control dimension is the millimeter column
Rev. P2.00
5
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